<date> can be one of the following formats:
today
yesterday
tomorrow
<last|past|prev|current|this|coming|next><week|month|year>
<last|past|prev|coming|next><x><minutes|hours|weeks|months|years>
january|february|march|april|may|june|july|august|september|october|november|december
jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec
sunday|monday|tuesday|wednesday|thursday|friday|saturday
sun|mon|tue|wed|thu|fri|sat
unknown
year
month/year
day/month/year

For example, I am trying to find files created or modified on 2015-10-31

How are dates displayed on your computer? 31/10/2015? 10/31/2015? 2015/10/31?

Type in dates in the same format as how they are displayed on your computer.

Please try searching for:
dm:31/10/2015

Use / to separate day/month/year.

I even tried this synatx with no results: 1:* dc:last1hours. I entered it in the search bar. The only search that works is wild cards or typing normal file names.

1:* should not match anything, what are you trying to search for here?

Note: Please make sure regex is disabled from the Search menu, search functions will not work when regex is enabled.
Please try the Everything 1.4 beta and look at Search -> Advanced Search... to help with search syntax.

This is VERY basic, but I had trouble with it so someone else might. I couldn't seem to get Everything to "sort by date" and I was going crazy. Turns out it was the way I had E set up. When I made ALL the Date Columns VISIBLE (modified, created, accessed and recently changed), the date-related functions worked. (Answer to an un-asked question, I guess.)

I have a specific search which brings to light some questions that may not be clear to other users too

The uncertainty regards:
1. operator priority e.g. regexexpression works but child:regex:expression does not
2. with OR syntax expressionSPACE|SPACEexpression and expression|expression seems to be equal
3. use of brackets <> can operators be inside brackets?
4. use of child: parameter ... it seems child:pic: doesn't work?
5. using OR statements in regex filename search as a workaround?
6. do operators only act on subsequent expressions until the next space e,g, is child:*.jpg|child:*.png the same as child:<*.jpg|*.png> the same and different to child:*.jpg child:*.png

Probably some basic coding issues lacking for me.

I am looking for:
- a list of folders
- that contain pictures
- where the pictures have names with 2016 2017 or 2018 in the filename (e.g. Screenshot_20161202.png or 20170104_123320.jpg)
- which may be in folders labelled in spanish or english
- excluding some folders

I might add an UI option to do this, for the next version of Everything I support two wildcard functions, one that is used in your common open file dialog, eg: *.txt and another which support character ranges with [], # = digit and backslash escapes (eg: \u00C6).
However, this is currently only used when searching content with the wildcard: modifier, such as wildcard:content:"[abc]*[123]"

In my experience there are VERY FEW people who know how to do Cmd.exe environment string replacement like the above.

FYI: I have long (20+ years) had a comp.cmd or comp.bat to feed "n" (No I don't want to compare more files) into comp.exe.
Stupid comp.exe was one of the poorest designed DOS/cmd programs ever. In DOS days, I used to just go in with a Hex editor and bypass the call to the "question" subroutine by changing one byte, but that's impractical today when working on dozens or tens of thousands of network computers.)

BTW: Another useful trick is to have a "file of Ns": In my Bat directory are 2 files named N and N.txt which have 64K lines of nothing but N (for No) to allow redirection to commands that ask questions but which only accept switches for Y(es) or have no switch at all to avoid such questions. Xcopy is in the former category, comp in the latter.